Safety brake for automotive vehicles



March 28, 1944. J. LA VIA SAFETY BRAKE FOR AUTOMOTIVE VEHICLES FiledNov. 15, 1941 INVENTOR 3 JOSEPH 14 ATTORNEY Patented Mar. 2a, 1944SAFETY, BRAKE FOB AUTOMOTIVE VEHICLES Joseph La Via, Ridgewood, N. 1!.Application November 15, 1941, Serial No. 419,264 3 Claims. (01.188-167) This invention relates to means for safely holding a parkedvehicle upon a grade, the principal object of the invention residing inthe provision of means to prevent accidental movement of a vehicle downa grade no matter in which direction the vehicle is pointed,

Many accidents have occurred because a parked vehicle, whether byaccidental release of its brakes or by impetus initiated by an outsideforce, rolled down grade out of control. Attempts have been made toprovide means for preventing such motion in a forward direction withregard to the front of the vehicle. However, of equal importance, andfor the sake of complete safety, it is desirable to prevent such motionrearward since vehicles are as frequently parked up grade as down grade.

An important object of the invention, therefore, is to Provide means foreffectively locking the drive or propeller shaft of a parked vehiclewhereby said vehicle cannot move either forward or backward on an up ordown grade.

The invention is particularly applicable to automotive vehicles, theinvention, therefore, contemplating the provision of means automaticallylocking the propeller shaft of such vehicles when its engine is notoperating, and automatically'releasing said shaft when the engine isoperating.-

To meet the fire laws of various communities, the invention furthercontemplates the provision of means for manually releasing the propellorshaft so that the vehicle may be moved from a site of danger.

The foregoing and other objects, features and advantages of theinvention, will become evident from the following specification in whichthe invention is described with regard to the illustrated embodimentthereof in the accompanying drawing which is intended as exemplary onlyof the invention. 1

In the drawing:

Fig. 1' is a side elevational view showing the invention applied. to anautomobile engine and propellor shaft, parts being shown in section andthe engine being fragmentary. i

Fig. 2 is an end view of a clutohing'unitemployed in the present lockingmeans.

Fig. 3 isa plan view of cam means employed for moving the clutchingmeans.

In that embodiment of the invention which is illustrated, the engine 5serves to drive the shaft 6 through the medium of a transmissionmechanism 1, said shaft being connected as through against rotation ineither direction.

the universal joint 8 to a drive or propellor shaft 9. The latter shaftin the usual way serves to drive the wheels of an automotive vehicle ascan be well understood.

When such a vehicle is parked on a grade, and should the parking brakesthereof become released or loosened, the momentum of a vehicle weighingseveral thousand pounds could cause considerable damage, the presentinvention contemplating means for' preventing such accidental motion ofa parked vehicle.

Means are provided for locking the shaft 6 and thus the propellor shaft9 to prevent rotation thereof in either direction whereby a vehicleparked on a grade is prevented from rolling down such grade eitherforward or backward. In the present instance, it is preferred to usemeans such as the clutch members Ill and, each carrying a plurality ofballs or rollers I2 having respective cooperative engagement with theconical seats l3 and I4 fixedly held as in a casing l5 fixed to the rearof the transmission unit 1. Spring means such as shown at l6 and I! orsimilar means maybe employed to urge the respective clutch members l0and H in a direction to cause the balls or rollers l2 to be held out ofcontact with the respective conical seats I3 and I4.

While the use of one of such clutching means may in some instances beeffective, it is preferred to use two, as illustrated, so that each mayeffectively perform its function in looking a shaft 6 Thus, a cam slotor groove I8 is provided for a pin IS on the clutch member In whereby awedging force is obtained between said pin and slot to more effectivelywedge the balls I! against the seat l3, such a force being greater thanif .the clutch member ID were merely slid longitudinally into lockingposition. The clutch member Ill, therefore, is most effective forlocking the shaft 6 in one direction. To look said shaft againstrotation in the other direction, a similar 'slot or groove 20 engagedwith a pin 2| is employed for the other clutching member H.

The unit device above described is intended to function to lock theshaft 6 when the vehicle is at rest, the force employed for moving theclutch members I0 and H into locking position being carried by meansabout to be described.

The cam shaft 22 or any other suitable moving member may be employed foroperating a device such as the governor 23 which controls the positionof a sleeve 24. Means such as a spring erating.

The movement of this sleeve may be employed -for controlling theclutching members l and II.

One manner of accomplishing this is to provide abracket 25a sopositioned as not to interfere with the floor of the vehicle and toprovide said bracket with a gear rack 2'6 arranged to drive a pinion 21carried by a stud 28 mounted on the housing IS. The stud 28 may reprovided with means such.as a cam 29, in the present instance said cambeing formed with opposed substantially identical lobes 30 and 3!. Thecam lobes I0 and 3| are so designed as to wedge the clutch members inand i l apart when the engine is idle and to release said members sothat the springs I8 and I! may become effective to urge them towafrdeach other.

From the above it may be seen that when the engine is not operating thespring 25 urges the sleeve 24 outwardly in projected position. The camlobes 30 and 3| in this position of the sleeve 24 are arranged to forcethe clutch members l0 and H toward the respective seats I3 and I4whereby the rollers 12 engage said seats. The movement of the clutchmembers as they are be ing forced into position by the cam, is bothaxial and rotational as imparted by the angle of the cam grooves I8 and20. Thus, an effective lock means being either placed under the hood' ofthe r vehicle or within the front compartment where is afforded for theshaft 6 which is held against rotation in either direction and therebyprevents accidental rolling of the parked vehicle.

The foregoing locking of the shaft occurs automatically upon stopping ofrotation of the shaft 22 which ceases its rotation upon stopping of theoperation or the engine.

When the vehicle is again to be driven, and the engine started, therotation of the shaft 22 causes the centrifugal force of the governor toovercome the force of the spring 25. The sleeve 24 is, therefore,retracted and the cam 29 partially rotated as shown by the dot-dashlines of Fig. 3, to release pressure on the clutch members. The springsi6 and i1 now become effective to completely release contact between theclutch balls l2 and the seats l3 and Hi. The vehicle may now be drivenwithout interference by the locking means. 1

A vehicle thus effectively locked could not be easily moved should itbecome necessary to remove it from a dangerous site such as in thevicinity of a fire. Means are, therefore, provided whereby the lockingmeans may be released, said it is readily accessible. In the presentinstance. this means may merely comprise a handle 32 by means of whichthe sleeve 24 may-be shifted to compress the spring 25 in the directionin which it is compressed by the centrifugal force of the governor. Thishandle may be locked in retracted position so that the car may either berolled or driven away from; the mentioned dangerous site.

From the foregoing, it may be seen that a simple, safe, and effectivemeans has been provided for locking a parked car on a grade. It isobvious that the principles of the invention may be varied within thespirit and scope of the appended claims. It is. therefore, intended thatthis disclosure be, considered as by way of example only. A

What I claim as new and desire to secure by Letters Patent, is:

1. In, an automotive vehicle having an engine and a member driventhereby, means for gripping said member to hold the same againstrotation in both directions, means including said engine for renderingsaid gripping means ineffective, said means comprising a governor drivenby said engine and spring means operating to eflect release of saidgripping means during operation of the engine and governor, and meansfor rendering said gripping means effective when and only when saidengine is not operating.

2. In an automotive vehicle having an engine and a member driventhereby, means for gripping said member to hold the same againstrotation in both directions, means including said engine for renderingsaid gripping means ineffective, said means comprising a governor drivenby said engine and spring means operating to effect release of saidgripping means during operation of the engine and governor, and meansfor rendering said gripping means efiective when and only when saidengine is not operating, said latter means including a spring and cammeans con trolled thereby to effect engagement of said gripping means.

3. In a device of the character described, a pair of shaft grippingunits each comprising a fixed clutch member and a movable clutch member,means keying each movable clutch member to said shaft, and means formoving said movable clutch members positively into clutching engagementwith the respective fixed clutch members,

said keying means comprising oppositely ar ranged helical grooves insaid shaft, and keys arranged in said grooves whereby the movable clutchmembers are oppositely rotated when moved into and out of engagementwith the fixed clutch members.

JOSEPH LA VIA.

